The House of Esterházy (also spelled Eszterházy) was a Hungarian noble family in Hungary beginning in the Middle Ages. From the 17th century they were among the great landowner magnates of the Kingdom of Hungary, during the time it was part of the Habsburg Empire and later Austria-Hungary. The Esterházys arose among the minor nobility of the northern part of the Kingdom of Hungary (today's southwest Slovakia). This is reflected in the full name of the family, Esterházy of Galantha, Galanta being a small town east of Bratislava, then capital of Hungary, now capital of Slovakia. The family rose to prominence under Count Nikolaus Esterházy (1583-1645) and his son, Prince Paul Esterházy (1635-1713). In the 17th century, after Nikolaus' acquisitions, the family split into four main family lines:

* the older Forchtenstein (Hungarian: Fraknó) line : founded by Nikolaus Esterházy, main seat: Eisenstadt (Kismarton)
* the younger Forchtenstein line
* the Zvolen (Zólyom) line: founded by Paul Esterházy (died 1641)
* the Csesznek line: founded by Daniel Esterházy (died 1654)

In 1626 the Esterházys were granted the title of Count and in 1712, the older Forchtenstein line received the title of (Ruling) Prince by the Holy Roman Emperor. The success of the family arose from the steady accumulation of land, and loyalty both to the Roman Catholic Church and to the Habsburg Emperor. The latter factor was perhaps the most important. A consistent theme of Hungarian history was an ardent and sometimes violent wish to become free of Austrian rule, a wish that was finally fulfilled at the end of the First World War. The Esterházy princes were consistently loyal to the Habsburg monarchy, and on several occasions rendered vital services to it in times of crisis. These included the Turkish siege of Vienna in 1683, and the outright occupation of Vienna by Napoleon in 1809.